kernel/linux.git/drivers/gpu/drm/drm_modes.c, branch v4.9.218

drm/modes: Prevent division by zero htotal

2019-02-15T07:07:38+00:00

commit a2fcd5c84f7a7825e028381b10182439067aa90d upstream. This patch prevents division by zero htotal. In a follow-up mail Tina writes: > > How did you manage to get here with htotal == 0? This needs backtraces (or if > > this is just about static checkers, a mention of that). > > -Daniel > > In GVT-g, we are trying to enable a virtual display w/o setting timings for a pipe > (a.k.a htotal=0), then we met the following kernel panic: > > [ 32.832048] divide error: 0000 [#1] SMP PTI > [ 32.833614] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.0-rc4-sriov+ #33 > [ 32.834438] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.10.1-0-g8891697-dirty-20180511_165818-tinazhang-linux-1 04/01/2014 > [ 32.835901] RIP: 0010:drm_mode_hsync+0x1e/0x40 > [ 32.836004] Code: 31 c0 c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 8b 87 d8 00 00 00 85 c0 75 22 8b 4f 68 85 c9 78 1b 69 47 58 e8 03 00 00 99 f9 b9 d3 4d 62 10 05 f4 01 00 00 f7 e1 89 d0 c1 e8 06 f3 c3 66 > [ 32.836004] RSP: 0000:ffffc900000ebb90 EFLAGS: 00010206 > [ 32.836004] RAX: 0000000000000000 RBX: ffff88001c67c8a0 RCX: 0000000000000000 > [ 32.836004] RDX: 0000000000000000 RSI: ffff88001c67c000 RDI: ffff88001c67c8a0 > [ 32.836004] RBP: ffff88001c7d03a0 R08: ffff88001c67c8a0 R09: ffff88001c7d0330 > [ 32.836004] R10: ffffffff822c3a98 R11: 0000000000000001 R12: ffff88001c67c000 > [ 32.836004] R13: ffff88001c7d0370 R14: ffffffff8207eb78 R15: ffff88001c67c800 > [ 32.836004] FS: 0000000000000000(0000) GS:ffff88001da00000(0000) knlGS:0000000000000000 > [ 32.836004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 32.836004] CR2: 0000000000000000 CR3: 000000000220a000 CR4: 00000000000006f0 > [ 32.836004] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 32.836004] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 32.836004] Call Trace: > [ 32.836004] intel_mode_from_pipe_config+0x72/0x90 > [ 32.836004] intel_modeset_setup_hw_state+0x569/0xf90 > [ 32.836004] intel_modeset_init+0x905/0x1db0 > [ 32.836004] i915_driver_load+0xb8c/0x1120 > [ 32.836004] i915_pci_probe+0x4d/0xb0 > [ 32.836004] local_pci_probe+0x44/0xa0 > [ 32.836004] ? pci_assign_irq+0x27/0x130 > [ 32.836004] pci_device_probe+0x102/0x1c0 > [ 32.836004] driver_probe_device+0x2b8/0x480 > [ 32.836004] __driver_attach+0x109/0x110 > [ 32.836004] ? driver_probe_device+0x480/0x480 > [ 32.836004] bus_for_each_dev+0x67/0xc0 > [ 32.836004] ? klist_add_tail+0x3b/0x70 > [ 32.836004] bus_add_driver+0x1e8/0x260 > [ 32.836004] driver_register+0x5b/0xe0 > [ 32.836004] ? mipi_dsi_bus_init+0x11/0x11 > [ 32.836004] do_one_initcall+0x4d/0x1eb > [ 32.836004] kernel_init_freeable+0x197/0x237 > [ 32.836004] ? rest_init+0xd0/0xd0 > [ 32.836004] kernel_init+0xa/0x110 > [ 32.836004] ret_from_fork+0x35/0x40 > [ 32.836004] Modules linked in: > [ 32.859183] ---[ end trace 525608b0ed0e8665 ]--- > [ 32.859722] RIP: 0010:drm_mode_hsync+0x1e/0x40 > [ 32.860287] Code: 31 c0 c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 8b 87 d8 00 00 00 85 c0 75 22 8b 4f 68 85 c9 78 1b 69 47 58 e8 03 00 00 99 f9 b9 d3 4d 62 10 05 f4 01 00 00 f7 e1 89 d0 c1 e8 06 f3 c3 66 > [ 32.862680] RSP: 0000:ffffc900000ebb90 EFLAGS: 00010206 > [ 32.863309] RAX: 0000000000000000 RBX: ffff88001c67c8a0 RCX: 0000000000000000 > [ 32.864182] RDX: 0000000000000000 RSI: ffff88001c67c000 RDI: ffff88001c67c8a0 > [ 32.865206] RBP: ffff88001c7d03a0 R08: ffff88001c67c8a0 R09: ffff88001c7d0330 > [ 32.866359] R10: ffffffff822c3a98 R11: 0000000000000001 R12: ffff88001c67c000 > [ 32.867213] R13: ffff88001c7d0370 R14: ffffffff8207eb78 R15: ffff88001c67c800 > [ 32.868075] FS: 0000000000000000(0000) GS:ffff88001da00000(0000) knlGS:0000000000000000 > [ 32.868983] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 32.869659] CR2: 0000000000000000 CR3: 000000000220a000 CR4: 00000000000006f0 > [ 32.870599] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 32.871598] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 32.872549] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > > Since drm_mode_hsync() has the logic to check mode->htotal, I just extend it to cover the case htotal==0. Signed-off-by: Tina Zhang Cc: Adam Jackson Cc: Dave Airlie Cc: Daniel Vetter [danvet: Add additional explanations + cc: stable.] Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/1548228539-3061-1-git-send-email-tina.zhang@intel.com Signed-off-by: Greg Kroah-Hartman

drm: Fix broken VT switch with video=1366x768 option

2017-02-01T07:33:02+00:00

commit fdf35a6b22247746a7053fc764d04218a9306f82 upstream. I noticed that the VT switch doesn't work any longer with a Dell laptop with 1366x768 eDP when the machine is connected with a DP monitor. It behaves as if VT were switched, but the graphics remain frozen. Actually the keyboard works, so I could switch back to VT7 again. I tried to track down the problem, and encountered a long story until we reach to this error: - The machine is booted with video=1366x768 option (the distro installer seems to add it as default). - Recently, drm_helper_probe_single_connector_modes() deals with cmdline modes, and it tries to create a new mode when no matching mode is found. - The drm_mode_create_from_cmdline_mode() creates a mode based on either CVT of GFT according to the given cmdline mode; in our case, it's 1366x768. - Since both CVT and GFT can't express the width 1366 due to alignment, the resultant mode becomes 1368x768, slightly larger than the given size. - Later on, the atomic commit is performed, and in drm_atomic_check_only(), the size of each plane is checked. - The size check of 1366x768 fails due to the above, and eventually the whole VT switch fails. Back in the history, we've had a manual fix-up of 1368x768 in various places via c09dedb7a50e ("drm/edid: Add a workaround for 1366x768 HD panel"), but they have been all in drm_edid.c at probing the modes from EDID. For addressing the problem above, we need a similar hack to the mode newly created from cmdline, manually adjusting the width when the expected size is 1366 while we get 1368 instead. Fixes: eaf99c749d43 ("drm: Perform cmdline mode parsing during...") Signed-off-by: Takashi Iwai Link: http://patchwork.freedesktop.org/patch/msgid/20170109145614.29454-1-tiwai@suse.de Reviewed-by: Ville Syrjälä Signed-off-by: Ville Syrjälä Signed-off-by: Greg Kroah-Hartman

drm: update kerneldoc for changes introduced by commits "16fadc2568e9" and "9671e228fb78"

2016-08-16T15:32:08+00:00

Describe the new parameter 'bus_flags' to of_get_drm_display_mode() in the kerneldoc comments and add kerneldoc comments to the new function drm_bus_flags_from_videomode(). Signed-off-by: Lothar Waßmann Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1471354477-25877-1-git-send-email-LW@KARO-electronics.de

drm/imx: convey the pixelclk-active and de-active flags from DT to the ipu-di driver

2016-08-08T09:44:20+00:00

The 'de-active' and 'pixelclk-active' DT properties are evaluated by of_parse_display_timing() called from of_get_drm_display_mode(), but later lost in the conversion from videomode.flags to drm_display_mode.flags. Enhance of_get_drm_display_mode() to also return the bus flags in a separate variable, so that they can be passed on to the ipu-di driver. Signed-off-by: Lothar Waßmann Signed-off-by: Philipp Zabel

drm: add a helper function to extract 'de-active' and 'pixelclk-active' from DT

2016-08-08T09:44:20+00:00

add a helper function to extract information about pixel clock and DE polarity from DT for use by of_get_drm_display_mode(). While at it, convert spaces to tabs in indentation in drm_modes.h. Signed-off-by: Lothar Waßmann Signed-off-by: Philipp Zabel

Merge tag 'topic/drm-misc-2016-06-07' of git://anongit.freedesktop.org/drm-intel into drm-next

2016-06-09T01:19:28+00:00

As promised, piles of prep work all around: - drm_atomic_state rework, prep for nonblocking commit helpers - fence patches from Gustavo and Christian to prep for atomic fences and some cool work in ttm/amdgpu from Christian - drm event prep for both nonblocking commit and atomic fences - Gustavo seems on a crusade against the non-kms-native version of the vblank functions. - prep work from Boris to nuke all the silly ->best_encoder implementations we have (we really only need that for truly dynamic cases like dvi-i vs dvi-d or dp mst selecting the right transcoder on intel) - prep work from Laurent to rework the format handling functions - and few small things all over * tag 'topic/drm-misc-2016-06-07' of git://anongit.freedesktop.org/drm-intel: (47 commits) drm/dsi: Implement set tear scanline drm/fb_cma_helper: Implement fb_mmap callback drm/qxl: Remove useless drm_fb_get_bpp_depth() call drm/ast: Remove useless drm_fb_get_bpp_depth() call drm/atomic: Fix remaining places where !funcs->best_encoder is valid drm/core: Change declaration for gamma_set. Documentation: add fence-array to kernel DocBook drm/shmobile: use drm_crtc_vblank_{get,put}() drm/radeon: use drm_crtc_vblank_{get,put}() drm/qxl: use drm_crtc_vblank_{get,put}() drm/atmel: use drm_crtc_vblank_{get,put}() drm/armada: use drm_crtc_vblank_{get,put}() drm/amdgpu: use drm_crtc_vblank_{get,put}() drm/virtio: use drm_crtc_send_vblank_event() drm/udl: use drm_crtc_send_vblank_event() drm/qxl: use drm_crtc_send_vblank_event() drm/atmel: use drm_crtc_send_vblank_event() drm/armada: use drm_crtc_send_vblank_event() drm/doc: Switch to sphinx/rst fixed-width quoting drm/doc: Drop kerneldoc for static functions in drm_irq.c ...

drm/doc: Switch to sphinx/rst fixed-width quoting

2016-06-03T18:58:24+00:00

Just fallout from switching from asciidoc to sphinx/rst. v2: Found more. Also s/\//#/ in the vgpu ascii-art - sphinx treats those as comments and switch to variable-width, which wreaks the layout. v3: Undo some of the hacks, rebasing onto latest version of Jani's series fixed it. Acked-by: Liviu Dudau Acked-by: Jani Nikula Signed-off-by: Daniel Vetter

drm/doc: Appease sphinx

2016-06-02T14:25:20+00:00

Mostly this is unexpected indents. But really it's just a demonstration for my patch, all these issues have been found&fixed using the correct source file and line number support I just added. All line numbers have been perfectly accurate. One issue looked a bit fishy in intel_lrc.c, where I don't quite grok what sphinx is unhappy about. But since that file looks like it has never seen a proper kernel-doc parser I figured better to fix in a separate path. v2: Use fancy new &drm_device->struct_mutex linking (Jani). Cc: Jani Nikula Cc: linux-doc@vger.kernel.org Cc: Jonathan Corbet Acked-by: Jani Nikula Signed-off-by: Daniel Vetter

drm: add missing drm_mode_set_crtcinfo call

2016-06-01T04:59:39+00:00

When setting mode via MODE_ID property, drm_atomic_set_mode_prop_for_crtc() does not call drm_mode_set_crtcinfo() which possibly causes: "[drm:drm_calc_timestamping_constants [drm]] *ERROR* crtc 32: Can't calculate constants, dotclock = 0!" Whether the error is seen depends on the previous data in state->mode, as state->mode is not cleared when setting new mode. This patch adds drm_mode_set_crtcinfo() call to drm_mode_convert_umode(), which is called in both legacy and atomic paths. This should be fine as there's no reason to call drm_mode_convert_umode() without also setting the crtc related fields. drm_mode_set_crtcinfo() is removed from the legacy drm_mode_setcrtc() as that is no longer needed. Signed-off-by: Tomi Valkeinen Reviewed-by: Daniel Vetter Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie

drm/mode: rework drm_mode_object_put to drm_mode_object_unregister.

2016-04-22T00:26:37+00:00

This changes the code to handle being called multiple times without side effects. The new names seems more suitable for what it does. Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie